Owning a swimming pool can be fun especially when you can jump into beautiful blue and clear water! The key though is making sure you have a balanced water chemistry. In the past, we’ve talked about chlorine, Calcium Hardness, Cyanuric Acid (CYA) but today we want to focus on pH and Total Alkalinity (TA). These two values are vital to your water chemistry and making sure your water remains blue and clear.


pH is a measure of how acidic or basic the pool water is. pH is measured on a scale from 0-14, with 7.0 being neutral. Below 7.0 is defined as being acidic, while levels above 7.0 are said to be basic or alkaline. To have pH in balance we must adjust the water with additions of pH decreasers (acid) or pH increases (bases) to help you obtain an optimal range of 7.2 – 7.6 which is standard optimal level in the swimming pool industry.

If your testing shows a pH value below 7.0; the water is in a corrosive (acidic) condition and you will need to add a base to bring the pH up. Please note, a low pH will weaken vinyl, strip heat exchangers and erode plaster. Whereas, if the pH is above 7.8, the water is considered basic and you must add acid to bring down the pH to prevent the formation of scale or calcium deposits on your tile, the filter, and the possibility of cloudy water. Another issue with a high pH is chlorine becomes less effective.

Total Alkalinity

Alkalinity is a pH buffer, meaning it helps to keep the pH from drastically moving up and down the pH scale by absorbing major changes to the waters before affecting the pH. Total Alkalinity (TA) is a close relative to pH and is a measure of how much of the alkaline substances there are in the water. In the swimming pool water, we are concerned with bicarbonate alkalinity, which should be between 80 parts per million (ppm) and 120ppm. When the TA is within this range, it prevents rapid pH changes and ultimately stabilizes the pH level.

When you want to achieve a swimming pool with balanced water chemistry, adjusting your pH levels is vital. Please note if your salt levels are high that will cause your pH to increase more rapidly. If you should have any questions, please don’t hesitate to contact us today!